The invention relates generally to the area of machine controls; and specifically, the invention provides a low cost machine control system designed around a programmable machine function controller.
Traditionally, machine function controllers have been used to control general machine operations, e.g. power and motor controls, spindles, start/stop, tool change functions, axis overtravels, etc. The apparatus disclosed herein provides the above; and in addition, circuits are provided which function in conjunction with the controller for producing signals to control the operation of a machine slide. In the preferred embodiment, elements are included for increasing and decreasing a programmed velocity which is then restored for use during a subsequent execution of the machine cycle.
In many situations, a panel of I/O devices, e.g., lights, push buttons, readouts, etc. may be mounted on a panel remote from the controller. This may be a main machine control station, a pendant mounted panel or an auxiliary control station. In prior art controls, these I/O devices are wired directly to the appropriate machine control circuits. This direct wiring represents a substantial cost in the machine construction.
The apparatus disclosed herein provides a serial data link for connecting remote machine control panels to the controller. Therefore, a pair of two conductor cables replaces the up to hundreds of wires otherwise needed. Further, in the preferred embodiment, the serial data link is used to continuously multiplex signals to the readouts thereby providing a real time display of information from the controller without the use of storage elements located with the readouts.